Make combobox observers able to observe multiple comboboxes.
[chromium-blink-merge.git] / ash / session_state_observer.h
blobde1b5333801e51934884c9f447da2b23db25d12c
1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef ASH_SESSION_STATE_OBSERVER_H_
6 #define ASH_SESSION_STATE_OBSERVER_H_
8 #include <string>
10 #include "ash/ash_export.h"
11 #include "base/basictypes.h"
13 namespace ash {
15 class ASH_EXPORT SessionStateObserver {
16 public:
17 // Called when active user has changed.
18 virtual void ActiveUserChanged(const std::string& user_id) {}
20 // Called when another user gets added to the existing session.
21 virtual void UserAddedToSession(const std::string& user_id) {}
23 protected:
24 virtual ~SessionStateObserver() {}
27 // A class to attach / detach an object as a session state observer with a
28 // scoped pointer.
29 class ASH_EXPORT ScopedSessionStateObserver {
30 public:
31 explicit ScopedSessionStateObserver(ash::SessionStateObserver* observer);
32 virtual ~ScopedSessionStateObserver();
34 private:
35 ash::SessionStateObserver* observer_;
37 DISALLOW_COPY_AND_ASSIGN(ScopedSessionStateObserver);
40 } // namespace ash
42 #endif // ASH_SESSION_STATE_OBSERVER_H_